Oh I completely agree with you. Good managers have an amazing multiplying effect on their team. People underestimate how important it is for a team to gel to be productive - although it's been said since the Peopleware days.

On the other hand, I've had maybe 2 great managers my entire career. The majority were either bean counters or empire builders. The latter is particularly toxic - they don't manage down at all beyond the minimum required. They focus almost exclusively on external optics and climbing the ladder.

So given that, I can see an appeal to trim down on managers. Of course, choosing the right managers to let go or convert is incredibly challenging.